1. Field of the Invention
The present invention is directed to a press having a fixed platen and a drive means including a plurality of crank assemblies which reciprocate the movable platen relative to the fixed platen, and which press can have either the impression force between the fixed and movable platens or the orientation of the surface of the movable platen adjusted.
2. Prior Art
Presses or platen presses which have a fixed platen mounted in a frame and a drive mechanism for reciprocating a movable platen relative to the fixed platen are used for processing material in the form of sheets or webs, for example of die cut paper board or corrugated board into box or carton blanks. Usually the fixed platen is mounted on a frame above the movable platen and the drive mechanism includes a plurality of crank assemblies each having a connecting rod extending to the movable platen for reciprocating the movable platen vertically in the frame relative to the fixed platen. The upper dead-center position of the movable platen corresponds to the press working position. To die cut a box blank from a sheet, the lower surface of the fixed platen as well as the upper surface of the movable platen which are in facing relationship may each be equipped with cutting and creasing tools. For this reason, the plane of the upper surface or working surface of the movable platen must be perfectly parallel with the plane of the working or lower surface of the fixed platen. In addition, the impression force of the press is obtained by adjusting the spacing between the two working surfaces of the fixed and movable platen when in the press working position.
Previous proposed designs for platen presses have the drawback of not including a device enabling an easy orientation of the upper plane of the movable platen or bed with regard to the surface of the fixed platen. To obtain an adjustment of the impression force, these press designs used devices which acted on the fixed platens and were independent of the device for orientating the upper planes of the movable platen.